---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-166540"
form_type: "8-K"
ticker: "IOBTQ"
cik: "0001865494"
company_name: "IO Biotech, Inc."
filed_at: "2023-06-14T23:59:59+00:00"
generated_at: "2026-06-14T01:36:53.305718+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# IO Biotech hits 225-patient enrollment milestone in Phase 3 melanoma trial; expanded to 380

## Summary
- 225 patients randomized in Phase 3 trial of IO102-IO103 + pembrolizumab for advanced melanoma.
- Interim ORR analysis now triggered; positive data could enable BLA for accelerated approval in U.S.
- Trial enrollment increased to 380 patients to potentially accelerate primary PFS endpoint.
- Company expects full enrollment by year-end 2023; cash runway through Q3 2024.
- CEO notes potential first vaccine approval in 2025 if interim analysis is positive.

## SEC filing metadata
- accession: 0001193125-23-166540
- form_type: 8-K
- ticker: IOBTQ
- cik: 0001865494
- company_name: IO Biotech, Inc.
- filed_at: 2023-06-14T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1865494/000119312523166540/0001193125-23-166540-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1865494/000119312523166540/d481906d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-166540
- JSON: https://secwatch.observer/filing/0001193125-23-166540.json
- Plain text: https://secwatch.observer/filing/0001193125-23-166540.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.